Fig. 5

Fig. 5 Muscle contraction affects chondrocyte intercalation in mice. (A) Length measurements of humeral and femoral growth plates in control and Sp^d mutant (humerus: p=0.0017; femur: p=0.027). (B) Quantification of cell number per constant area in control and Sp^d embryos (p=0.1266). An area of 8732.73 μm², corresponding to the boxed area in (D) in the humerus growth plate was used for calculation; 4–7 sections from each embryo were analyzed. (C) Quantification of the mean length-to-width ratio of chondrocytes from control and Sp^d humeral growth plates (F_15.5=71.07, p=0.0002). (D) H&E staining of control (upper panel) and Sp^d (lower panel) humeral growth plates; magnification of the boxed areas is shown on the right. Circles highlight the columnar organization of chondrocytes. (E, F) Comparison of chondrocyte column lengths between control and Sp^d embryos: Distribution of columns by number of cells per column in the humerus (E; X₁²=13.093, p=0.0003) and femur (F; X₁²=14.192, p=0.00017). (G, H) Distribution of angles between adjacent columns in control and Sp^d mutant in the humerus (G) and femur (H). Both distributions were found to be significantly different (see Table 1 and Table 2). Measurements were made on 4–5 controls and 4–5 mutant embryos from 3–4 different litters; scale bar represents 50 μm.